Hydrocarbon producing formations typically have sand commingled with the hydrocarbons to be produced. For various reasons, it is not desirable to produce the commingled sand to the earth's surface. Thus, sand control completion techniques are used to prevent the production of sand.
A commonly used sand control technique is a gravel pack. Gravel packs typically utilize a screen or the like that is lowered into the borehole and positioned adjacent a hydrocarbon producing zone, which is to be completed. Particulate material, collectively referred to as “gravel,” is then pumped as slurry into the borehole. The liquid in the slurry flows into the formation and/or through the openings in the screen resulting in the gravel being deposited in an annulus formed in the borehole between the screen and the borehole. The gravel forms a permeable mass or “pack” between the screen and the producing formation. The gravel pack allows flow of the produced fluids therethrough while substantially blocking the flow of any particulate material, e.g. sand.
In openhole completions that are gravel packed, a drilling fluid residue is often left on the formation adjacent to the borehole in the form of a filter cake, which must be removed to produce the adjacent formation. Filter cake removal treatments are conventionally done through coiled tubing after gravel packing is complete. To remove the filter cake, the gravel pack tubing is removed from the borehole and the coiled tubing for filter cake removal is run-in. Breakers, acids or other chemicals are pumped through the coiled tubing into the borehole to remove the filter cake. After the filter cake is removed, the coiled tubing is removed from the borehole and the final production/injection tubing is then run in.
Such repetitive steps of running and removing multiple work strings into the well is extremely time consuming and costly. It is even more time consuming and costly for completing boreholes with multiple producing zones within the same formation because each zone is typically completed and produced one at a time. It is highly desirable to complete all zones in a single trip.
There is a need, therefore, for new systems and methods for gravel packing that reduce the number of trips downhole needed to gravel pack multi-zone wells.